LS1/2 - GQ/GU Conversion questions.

[Hobbz]

Does a standard LS1 have enough grunt for a 2400 kg winch comp truck ?
Can the 4L60 handle the abuse ? Any modifications needed, sump, converter or shift kit ?
Anyone used Marks4wd 4L60 - GQ/GU Transfer adaptor kit ? anyone used this ?

Thanks.

[bogged]

Does a standard LS1 have enough grunt for a 2400 kg winch comp truck ?.

if a 70kw 4.2 petrol does, IM fairly sure that an LS1 should piss it in.

[bigbluemav]

Whilst I haven't driven a 4B with either engine it, I have owned commodores with both the LS1 (5.7 litre) and L76 (6.0 Litre). The L76 has LOADS more low down power than the LS1. I can't speak for the LS2, which is the same displacement (6.0 litres) as I haven't owned one (HSV's only).

Obviously the LS1 would be cheaper (more available), but the L76 (from VZ series II) and the L98 (VE comm's) are a far better option for a 4B due to more low down grunt.

Just my 2c worth.


Dave Mc

[Hobbz]

Should have worded my question better ... LS1 over LS2 .. sure a Ls2 makes more power, but is the difference more than marginal ? because the price is.

[bigbluemav]

Should have worded my question better ... LS1 over LS2 .. sure a Ls2 makes more power, but is the difference more than marginal ? because the price is.

The LS2 is the "go faster" version, whereas the L76 is the more pedestrian one. Seat of the pants feel is that the L76 has WAY WAY more low down power than the LS1.

When I first drove the VXSS (LS1), I hadn't driven a V8 since the XAGT coupe that I sold in 1988. What really struck me about it was the TOTAL LACK of low down grunt, that the old school V8's have have buckets of. The grunt caught up as revs rose and they rev harder than a cleveland (DERRRRR!!!). But no low down grunt. Same as an BF XR8 I took for a whirl.

But the 6.0 L VZSS was a TOTALLY different story, heaps more down low, and still heaps of power in the mid and upper rev range.

$$ is always an issue, but the L76 is better for low down,which is what we more often use out bush.

Dave Mc

[NutterGQ]

Should have worded my question better ... LS1 over LS2 .. sure a Ls2 makes more power, but is the difference more than marginal ? because the price is.

The LS2 is the "go faster" version, whereas the L76 is the more pedestrian one. Seat of the pants feel is that the L76 has WAY WAY more low down power than the LS1.

When I first drove the VXSS (LS1), I hadn't driven a V8 since the XAGT coupe that I sold in 1988. What really struck me about it was the TOTAL LACK of low down grunt, that the old school V8's have have buckets of. The grunt caught up as revs rose and they rev harder than a cleveland (DERRRRR!!!). But no low down grunt. Same as an BF XR8 I took for a whirl.

But the 6.0 L VZSS was a TOTALLY different story, heaps more down low, and still heaps of power in the mid and upper rev range.

$$ is always an issue, but the L76 is better for low down,which is what we more often use out bush.

Dave Mc

Ls1's in commodores are torque locked at low rpm, flash tune or aftermarket management eliminates this completely.

[eighty80]

that lack of low down power u refer to from the LS1 (I own a VX SS) disappears once u fit a proper set of headers and exhaust - try y's if your after better low down, or 4 into 1s if your after better top end and its got heaps down low.

LS1 edit and your pushing roughly 225 at the wheels / 300kw at the fly wheel...same sort of performance as the GTS at a fraction of the price.

Go the LS1 in the GQ...you will save heaps..

[bogged]

Go the LS1 in the GQ...you will save heaps..

the dude asking is in Denmark... that maynot be the case.

[eighty80]

opps...i didnt see he was from denmark

[bigbluemav]

that lack of low down power u refer to from the LS1 (I own a VX SS) disappears once u fit a proper set of headers and exhaust - try y's if your after better low down, or 4 into 1s if your after better top end and its got heaps down low.

LS1 edit and your pushing roughly 225 at the wheels / 300kw at the fly wheel...same sort of performance as the GTS at a fraction of the price.

Go the LS1 in the GQ...you will save heaps..

Had that (pipes and exhaust), but no edit. Still HEAPS more low down power in a L76. THat's "seat of the pants".


Dave Mc

[eighty80]

get the edit...WELL worth it mate...

your only a quarter of the way there without the edit...its amazing how out of tune they are out of the factory..

[bigbluemav]

At the risk of being painful................................once you factor in the cost of the edit ($1000 give or take??) how much closer does that get you to the total cost of L76?


Dave Mc

[gouldy]

Mate plenty of comp trucks run the LS1 and with a mafless tune, big exhaust and intake it will have 300kw easily. I have a GQ ute with a 2004 model LS1 with 285 kw standard plus the above mods and it is very good down low. the 6.0l is slightly better in standard form compared with a standard LS1 5.7.

LS1 also has a cable operated throttle body but the 6.0L LS2/L98/L76 has an electronic throttle body. ( probably not the best option in the mud/water) I believe that GM Performance has larger capacity LS1 short motors so your options are good later on down the track.


cheers
Gouldy

[killalux]

Mate there are plenty of winch truck here in QLD that are running stock LS1's with just a re-tune on he computer, and they all seem pretty happy with the power levels.

[Hobbz]

Thanks for all the answers, we will try to source a engine from the states ...
What about the standard auto ? is it viable solution or ?

[stuee]

At the risk of being painful................................once you factor in the cost of the edit ($1000 give or take??) how much closer does that get you to the total cost of L76?


Dave Mc

Most people will end up going in to get a mafless tune done or remove/add some functions of the pcm (BCM etc). Even an edit on the L76 is worth it. In saying that an edit for the pcm's is freely available here but what about in Denmark?

The biggest advantage the L76 (U.S market L98 with cylinder deactivation removed) is the head design. They are far superior to the cathedral port type heads used on the LS1/6/2. Basically the heads used on the L76 are production versions of the race heads developed in GM's race program for the C5R corvette or whatever it is. A lot of people upgrade the heads on LS1/2's with standard L76 heads as they are a cheap alternative to buying after market cast heads and generally easier to achieve gains compared to porting the cathedral style heads.

LS1 also has a cable operated throttle body but the 6.0L LS2/L98/L76 has an electronic throttle body. ( probably not the best option in the mud/water)

Early LS2's used cable throttle bodies. Its possible to run the earlier PCM's (ie cable throttle) with later style engines. This involves adapting the knock sensors, changing the reluctor wheels and sensors and the cam shaft sensor. Obviously you need to source a cable throttle to suite the later style manifolds (can be big $$$).

I believe that GM Performance has larger capacity LS1 short motors so your options are good later on down the track.
cheers
Gouldy

6.0L Gen III iron blocks (to suite Ls1 and Ls6) are available from GM. These were used in their pickups. They are quite heavy but favoured by the high performance crowd due to their increased strength when dealing with boost.


In terms of the transmission the 4L60e is on the week side. If weight is not an issue you want to source a 4l80e. If weight is an issue try and source a 4L65e. Ideally for competition work the two light duty transmission will need some work done if your going to be thrashing them.

[killalux]

There are quite a few places that do a 'mail order tune', Where you send your PCM to them the load in a 300kw maffless tune, and send it back. Not perfect way to do it but may be the better option.

Or you can buy the LS1 edit software for around $1000 then just it to someone with a dyno, And hope they can work it out.

The 4l60e auto would hold together, i would get the shift points altered and line pressure changed (all done with a tune on the PCM), but if you are buying the engine from the states, I would look at getting the 4L80e trans. It is heaps stronger, and should be easier to find in the US then here.
steve

[TheBigBoy]

Yep, I have a ls1 in my GU. 290bhp with 33's on. Theres a lot of differences between the 6 litre and the 5.7. I was lucky and got a vy 5.7 with the cable throttle body. Just another thing Id have to figure out otherwise and they add up quick. But it all comes down to the computer and maffless tune. As stated. Im running a EMS6680 which I chose as its pretty commonly used around the dyno guys. But my mate with his 80 series went a more expensive motech. Not to be out done he also went some heads and cam. He has 420bhp now.
BUT MAKE SURE YOU DONT GO AN IMPORT LS1, THEY ARE TOTALLY DIFFERENT!!!... AND THE SAME MODS AS MINE ONLY PRODUCES 210...

[TheBigBoy]

How do i put a pic up?

[killalux]

Yep, I have a ls1 in my GU. 290bhp with 33's on. Theres a lot of differences between the 6 litre and the 5.7. I was lucky and got a vy 5.7 with the cable throttle body. Just another thing Id have to figure out otherwise and they add up quick. But it all comes down to the computer and maffless tune. As stated. Im running a EMS6680 which I chose as its pretty commonly used around the dyno guys. But my mate with his 80 series went a more expensive motech. Not to be out done he also went some heads and cam. He has 420bhp now.
BUT MAKE SURE YOU DONT GO AN IMPORT LS1, THEY ARE TOTALLY DIFFERENT!!!... AND THE SAME MODS AS MINE ONLY PRODUCES 210...

May i just ask, why did you guys use aftermarket management?? The standard LS1 ECU with the right software is just a tune-able as any aftermarket ECU, And i will start easily and run better (in my experience).
The only advantage of the aftermarket ECU is data logging.

steve

[TheBigBoy]

killalux - Mine was 1 of the first (aussie) ls1's patrols in aus. Took 6 months to do. Even marks 4x4 adaptors hadnt done 1. It was sooo hard to do with the stock comp. I originally wanted to just have the first fully intergraded ls1 around. I had 3 dyno guys and a holden computer guy on my side. And every 4x4 comp guy around adding their input. To start with its illegal to unlock the computer, even though i had the ignition modual control and coded key. Every gear in the holden 6 speed has its own program etc.. But i wanted to keep it tough and keep the patrol 5 speed. So it had to be unlocked. Every sensor or program you dont/cant hook up you lose power. And in the end as soon as i changed to an aftermarket comp. Boosted the hp instantly. Mine was only fully rebuilt with standard inners. from a 297kw engine, add the after market comp. 300bhp. work that back to the fly considering you lose 40% power through a patrol driveline +33's. Thats a hell of alot of extra power.

So to sum it up, it was easier and made more power. The dyno guy had it in and running in 3 hours.

[TheBigBoy]

To this day i havent known any comp guys that run the stock computer after installing the ls1's to a 4x4. Do you know someone?

[killalux]

I have done several ls1's into winch trucks, Including a stroked, supercharged LS2 running 900HP flywheel, down to a stock LS1 with 240BHP on 37's, All on a stock computer, The factory computer is capable of running just about any engine mod.
I can understand using aftermarket it if you were one of the first around to do it, But would deinatly not advise doing it that way now, With the amount of people around now with LS1 edit software it is so easy to tune, And they aren't hard to wire the factory computer, or unlock them.

I would have a LS1 wired and fired up in a day no worries using stock ECU.
steve

[TheBigBoy]

See how the times have changed.

I just saw all your prices aswell at the bottom of your box. Mine cost $25k

I gave it a good crack though trying to run the standard comp. Only took a week to make the engine mounts and fit the engine. Another week for custom made extractors and exhaust. The rest of the time was all about the computer and wirring... Gave me such a headache!! I ended up selling the comp, modular, wirring loom, coded key (everything) for $300.

So do you think a standard comp is better and will give me the same horse power and run better than an after market 1?

[killalux]

In my opinion yes the factory computer can give you the same HP, as long as you get a good tuner.
And the good part is you still keep all the factory settings for start up, idle control, cold start enrichment, etc So it will start and run just like any commodore on the road. If you are happy with what you got now i wouldn't change it, But if you were doing a conversion from scratch, go factory ECU.
steve

[TheBigBoy]

Yep, ive already had to change my idle air controller and get my cold start redone. Its sucks being the test subject. But hey, someone has to be...

Im looking to supercharge mine later down the track. With a liquid to air intercooler. But im having real problems with getting enough air. I dont want to run 2 snorkles. Any idea's?

Also what size fuel pump are you running? my 500hp pump can only just keep up now.

[killalux]

Hey, I use a standard commodore pump in my truck, Others have used bosch 044 external pumps, The 900HP one uses 2 of them.

The supercharged truck uses a single 4" snorkle, I guess it does the trick.

[heathgu]

hey steve we had to use a 5" snorkel on the supercharged one cause 4" was not enough.

[TheBigBoy]

What supercharger did you use? boost and gain etc.. . I have a stock airtec/nissan snorkle and its not enough already. Even with a commodore air box. Detatch the throttle body and gives me an extra 20bhp.

Any side affects? heat issues?

[killalux]

hey steve we had to use a 5" snorkel on the supercharged one cause 4" was not enough.

Oh ok my bad, it doesn't look that big.